Intercalates formed with polypropylene/maleic anhydride-modified polypropylene intercalants

ABSTRACT

A nanocomposite concentrate composition comprising about 10 weight percent to about 90 weight percent of a layered silicate material and about 10 weight percent to about 90 weight percent of a matrix polymer comprising about 90-99.8% by weight of a polyolefin and about 0.2% to about 10%, preferably about 0.2% to about 3%, more preferably about 1% to 3% by weight, of a maleic anhydride-modified polyolefin, based on the total weight of polyolefins, wherein the layered silicate material is dispersed uniformly throughout the matrix polymer. Shearing of the concentrate and later (after shear) addition of an added matrix polymer avoids thermal degradation of the added matrix polymer and optimizes the dispersion of the nanomer throughout the matrix polymer; provides increased tensile strength; and reduces degradation of the polymer by melt formation of a concentrate thereby decreasing heat degradation of added matrix polymer.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation-in-part of application Ser.No. 09/515,768 filed Mar. 1, 2000.

FIELD OF THE INVENTION

[0002] The present invention is directed to intercalated layeredmaterials and, optionally, exfoliates thereof, prepared by intercalatinga layered material, e.g., a phyllosilicate, such as a smectite clay,with a polyolefin intercalant, preferably polyethylene and/orpolypropylene, and a maleic anhydride-modified polyolefin intercalant.The intercalated layered material, preferably in the form of aconcentrate, is combined with a polyolefin matrix polymer since theaddition of a polyolefin matrix polymer, after shearing the concentratefor exfoliation, avoids degradation of the polyolefin matrix polymer,added after shearing of the concentrate. The polyolefin and a maleicanhydride-modified polyolefin polymer can be intercalated in the form ofa polymer or an oligomer capable of polymerization to form the polymer,(e.g., an ethylene oligomer or polymer and/or a propylene oligomer orpolymer and/or copolymers thereof) or, can be unexpectedly easilyintercalated as the oligomer or polymer by direct compounding, e.g., bycombining the polyolefin oligomer and/or polymer in a mixing orextruding device at or above the polyolefin polymer melt temperature, toproduce the intercalated layered material and, subsequently, thenanocomposite by addition of matrix polyolefin polymer.

BACKGROUND OF THE INVENTION AND PRIOR ART

[0003] It is well known that phyllosilicates, such as smectite clays,e.g., sodium montmorillonite, sodium bentonite, calcium bentonite, andcalcium montmorillonite, can be treated with organic molecules, such asorganic ammonium ions, to intercalate the organic molecules betweenadjacent, planar silicate layers, for subsequent intercalation of anoligomer or polymer between the layers, thereby substantially increasingthe interlayer (interlaminar) spacing between the adjacent silicatelayers. The thus-treated, intercalated phyllosilicates, havinginterlayer spacings increased by at least 3 Å, preferably at least 5 Å,e.g., to an interlayer (interlaminar) spacing of at least about 10-25 Åand up to about 100 Angstroms, then can be exfoliated, e.g., thesilicate layers are separated, e.g., mechanically, by high shear mixing.The individual silicate layers, when admixed with a matrix polymer,e.g., a polyamide—see U.S. Pat. Nos. 4,739,007; 4,810,734; and5,385,776—have been found to substantially improve one or moreproperties of the polymer, such as mechanical strength, barrierproperties and/or high temperature characteristics.

[0004] Exemplary prior art composites, also called “nanocomposites”, aredisclosed in published PCT disclosure of Allied Signal, Inc. WO 93/04118and U.S. Pat. No. 5,385,776, disclosing the admixture of individualplatelet particles (exfoliated platelets) derived from intercalatedlayered silicate materials, with a polymer to form a polymer matrixhaving one or more properties of the matrix polymer improved by theaddition of the exfoliated intercalate. As disclosed in WO 93/04118, theintercalate is formed (the interlayer spacing between adjacent silicateplatelets is increased) by adsorption of a silane coupling agent or anonium cation, such as a quaternary ammonium compound, having a reactivegroup which is compatible with the matrix polymer. Such quaternaryammonium cations are well known to convert a highly hydrophilic clay,such as sodium or calcium montmorillonite, into an organophilic claycapable of sorbing organic molecules.

[0005] Maxfield U.S. Pat. No. 5,514,734 ('734) discloses intercalationof clay with both a coupling agent (silane, titanate or zirconate) andonium ions together with in-situ polymerization of a nylon polymerprecursor, such as polymerizable nylon monomers, e.g., ε-caprolactam,capable of in-situ polymerization to form a polymer that is reactivewith the coupling agent to tether the polymer to the clay platelets. Inaccordance with the present invention, a coupling agent-reacted andonium compound-intercalated layered silicate material is polymer meltprocessed for unexpectedly better dispersibility of the exfoliatedplatelets throughout a matrix polymer, particularly non-polar matrixpolymers, such as polyolefins, especially polyethylene and/orpolypropylene. In accordance with the present invention, the couplingagent preferably is not reactive with the matrix polymer, so that thematrix polymer is not tethered to the clay platelets. The Maxfield '734patent is hereby incorporated by reference for its disclosure ofcoupling agents useful in accordance with the present invention.

OPTIONAL COUPLING AGENT REACTION

[0006] Edges of clay layered materials are replete with hydroxy groups(—OH) that make it extremely difficult to intercalate non-polar and lowpolarity oligomers and polymers. In accordance with the preferredembodiment of the present invention, as disclosed in co-pendingapplication Ser. No. 09/516,136 filed Mar. 1, 2000, it has been foundthat by reacting the —OH groups at the edges of clay platelets with acoupling agent, to form coupling agent covalent bonds at the clay edges,the clay becomes much more receptive to intercalation of such non-polarand low polarity oligomers and polymers, particularly polyolefins suchas ethylene and propylene homopolymers and copolymers. It should beunderstood, however, that it is not essential to react the layeredmaterial edges with a coupling agent in accordance with the presentinvention since polyolefin intercalant(s) can be intercalated withoutthe coupling agent reaction, particularly when incorporating arelatively small percentage, e.g., about 0.1-10% by weight, preferablyabout 0.2% to about 3% by weight, more preferably about 1% to about 3%,most preferably about 1% to about 2% by weight of a maleicanhydride-modified polyolefin in addition to the polyolefin intercalant.To achieve the full advantage of the present invention, the maleicanhydride-modified polyolefin should have a weight average molecularweight of at least about 5,000, preferably at least about 10,000, morepreferably at least about 40,000.

[0007] Useful coupling agents include those selected from the groupconsisting of silanes, titanates, aluminates, zirconates, and mixturesthereof, particularly the organosilanes, organotitanates,organoaluminates and/or organozirconates. The coupling agent(s) can bereacted with the —OH functionalities at the edges of the layeredmaterial platelets by contacting the layered material, before, during,or after onium ion intercalation, with the coupling agents in the formof a gas, neat liquid, finely divided (e.g., non-colloidal) solid, orsolute in a solvent. While onium ion intercalation is preferred, itshould be understood that onium ion intercalation also is not necessaryin accordance with the present invention when a relatively small amountof maleic anhydride-modified polyolefin, e.g., 0.2% to 10%, based on thetotal weight of polyolefin and maleic anhydride-modified polyolefincontacting the clay, is incorporated into the clay together with thepolyolefin. The concentration of coupling agent, when used, should be atleast about 0.1%, preferably in the range of about 0.1% to about 10% byweight, more preferably in the range of about 0.5% to about 6% byweight, and most preferably about 1% to about 4% by weight, based on thedry weight of the layered material. The preferred coupling agents have astructure as follows:

[0008] wherein x=Si, Ti, Zr or Al

[0009] wherein R₁ is an organic radical, preferably an alkyl radical oran amine radical, bonded directly to the Si, Ti, Zr or Al atom (x) andat least one of R₂, R₃ and R₄ is a radical containing a functionality,preferably an organic functionality, capable of a condensation reactionwith a hydrogen from the —OH groups at the edges of the layeredmaterial, preferably selected from H, halogen, alkoxy, acyloxy andamine.

[0010] The —OH reaction of the coupling agent, e.g., silane, can beaccomplished by either adding the silane to a dry onium-intercalatedclay, i.e., organoclay, or by adding the silane to a water slurry of theorganoclay, followed by removal of by-products and solvent during heattreatment. Alternatively, the silane also be added to thepolymer-organoclay nanocomposite by integral blend methods. In thismethod, undiluted silane is added to the polymer either before or afterintroduction of the onium-intercalated clay or organoclay. It ispreferable to add the silane before introduction of the clay becausethis allows for better dispersion and distribution of the silane intothe polymer.

[0011] In addition to, or instead of, the platelet edge —OH reactionwith a coupling agent, the layered material also is intercalated withonium ions, e.g., ammonium ions, having a general structure of:

[0012] Where R₁ is a C₂-C₂₂ alkyl chain, straight chain or branched, andR₂, R₃ and R₄, same or different, is hydrogen or an alkyl aryl or alkylmoiety, preferably a is C₁-C₈ alkyl chain.

[0013] In accordance with an important feature of the present invention,the layered material is intercalated with a substantial majority ofpolyolefin, e.g., about 90% to about 99.8% by weight polyolefin,preferably a polypropylene homopolymer, and about 0.2% to about 10%,preferably about 1% to about 5%,more preferably about 1% to about 3% byweight maleic anhydride-modified polyolefin, based on the total weightof the intercalant oligomers or polymers and intercalated matrixpolymer. The resulting polyolefin/modified polyolefin intercalatednanocomposite has improved mechanical properties and heat stability overtraditional polyolefin-intercalated nanocomposites, it is theorized dueto the combination of the polyolefin with a maleic anhydride modifiedpolyolefin enabling more complete intercalation of the polyolefinintercalants between clay platelets for surprisingly better exfoliationand dispersibility of clay platelets and fewer, thinner tactoids.

OPTIONAL ONIUM ION INTERCALATION

[0014] The interlaminar spacing of adjacent layers (platelets) of thecoupling agent-reacted layered material is expanded at least about 3 Å,preferably at least about 5 Å, to a basal spacing of at least about 10Å, preferably to at least about 15 Å, and usually to about 18 Å in anymanner known in the art, preferably by contacting the layered materialwith an onium ion spacing agent for subsequent intercalation withpolyolefin and maleic anhydride-modified polyolefin oligomers orpolymers. The optional onium ion may be primary, secondary, tertiary orquaternary and preferably is a long chain (C₆+) onium ion spacing agenthaving at least one binding (ion-exchange) site capable ofion-exchanging or replacing Li⁺, Na⁺, K⁺, Ca⁺, Mg⁺², or other inorganiccations that occur within the interlayer spaces between adjacent layersor platelets of the layered materials. The association of the layeredmaterial inorganic cations with the onium ion spacing agent viaion-exchange enables the conversion of the hydrophilic interior clayplatelet surfaces to hydrophobic platelet surfaces. Therefore, oligomersor polymers can be easily intercalated between adjacent platelets of thelayered material, e.g., smectite clay platelets, after onium ionintercalation.

[0015] In accordance with the preferred embodiment of the presentinvention, an olefin oligomer or polymer, such as polyethylene,polypropylene or copolymers thereof, having a weight average molecularweight between about 100 and about 5 million, preferably about 1,000 toabout 500,000, and about 10% to about 90%, preferably about 25% to about50% by weight of a maleic anhydride-modified polyolefin, having a weightaverage molecular weight of at least about 5,000, preferably at leastabout 10,000, is intercalated between adjacent platelets of the layeredmaterial, to form an intercalate concentrate. Alternatively, the layeredmaterial can be intercalated with the polyolefin and maleicanhydride-modified polyolefin directly with the matrix polymercontaining both the polyolefin and maleic anhydride-modified polyolefin,after onium ion intercalation. Optionally, the intercalate concentrateis sheared to exfoliate the intercalate into a predominance ofindividual platelets. The concentration of intercalate, or exfoliatethereof, should be in the range of about 10-90% by weight, preferably20-80%, more preferably 30-60% by weight in the concentrate. Theconcentrate is then mixed into a matrix polymer, comprising a polyolefinoligomer or polymer and a maleic anhydride-modified polyolefin oligomeror polymer, i.e., by direct compounding of the intercalated layeredmaterial with the polymers. The combination of matrix polymerpolyolefin(s) and the initial formation of an intercalateand/or/exfoliate concentrate, results in a completely homogeneousdispersion of intercalated layered material and/or exfoliated platelets.

[0016] Maleic anhydride-modified polypropylene (MA-PP) oligomers andpolymers are well known for use in making nanocomposites, as disclosedin Hasegawa, et al. Preparation And Mechanical Properties OfPolypropylene—Clay Hybrids Using A Maleic Anhydride-ModifiedPolypropylene Oligomer, Journal of Applied Polymer Science, Vol. 67,pages 87-92 (1998), hereby incorporated by reference. It has been foundthat the higher molecular weight maleic anhydride-modified polyolefins,having a weight average molecular weight of at least 10,000, preferablyat least 40,000, provide much better mechanical properties, such asstrength and temperature resistance. If the weight average molecularweight is too low, e.g., below about 5,000, the maleicanhydride-modified polyolefin will perform as a plasticizer and decreasethe properties of the polyolefin in the nanocomposite; if the weightpercentage of the maleic anhydride (measured as a weight of maleicanhydride only) is too high, e.g., above about 5% by weight, based onthe weight of the maleic anhydride-modified polyolefin, the maleicanhydride-modified polyolefin will not be compatible with neatpolyolefins; if too low, e.g., below about 0.2% by weight, the resin haslimited compatibility with the modified montmorillonite.

[0017] The maleic anhydride-modified polypropylene (MA-PP) oligomerdescribed in the Hasegawa et al. article from Sanyo Chemical Industries,having an acid value of 52 mg KOH/g, a softening temperature of 145° C.,and a weight average molecular weight of about 30,000, is suitable inaccordance with the present invention. However, any other availablemaleic anhydride-reacted polyolefin, preferably polypropylene, also issuitable in accordance with the principles of the present invention. TheHasegawa et al. article teaches using a minimum ratio of maleicanhydride-modified polypropylene (MA-PP) to polypropylene homopolymer(PP) of 7% by weight MA-PP to 93% by weight PP, when the combination isused to form a nanocomposite. In accordance with the present invention,it has been found that best results are achieved by incorporating amatrix polymer combination of a polyolefin and a maleicanhydride-modified polyolefin, having about 0.2% to about 10% by weightmaleic anhydride-modified polyolefin, preferably about 1% to about 5% byweight maleic anhydride-modified polyolefin, more preferably about 1% toabout 3% by weight maleic anhydride-modified polyolefin and polyolefincombined with the clay.

[0018] Optionally, the nanocomposite concentrate can be sheared toexfoliate up to 100% of the tactoids or platelet clusters intoindividual platelets, preferably such that more than 80%; or more than90% by weight of the layered material can be completely exfoliated intosingle platelet layers. Quick, easy, and completely homogeneousdispersion of the co-intercalated layered material in a polyolefinmatrix polymer is achieved and the resulting nanocomposite hasunexpectedly easy polymer intercalation and homogeneous dispersion ofthe intercalate and/or exfoliate throughout the matrix polymer.Additional matrix polymer, particularly a polyolefin, can be added aftershearing so that the added matrix polymer, particularly polyolefin, isnot degraded by substantial shearing and is subjected to limited hightemperature degradation.

[0019] The intercalates of the present invention preferably aredispersed uniformly into a matrix polymer that is a combination ofpolypropylene and maleic anhydride-modified polypropylene to form apolymer/clay intercalate-containing nanocomposite and/orpolymer/exfoliate-containing nanocomposites by direct compounding of thepolyolefin-intercalated clay with sufficient matrix oligomers or matrixpolymers to form a concentrate, that can later be mixed with additionalmatrix polymer, without subsequent polymer-degrading shear, to form ananocomposite. The intercalate concentrate can be directly compoundedwith the additional pristine matrix polymer, preferably the same as thepolymer intercalant, to form a nanocomposite easily, while achieving ananocomposite material with homogeneously dispersed platelets. Theintercalate of the present invention can also be prepared with polymersolutions as well as polymer emulsions. This processing route willeliminate the melt compounding process and reduce thermal degradation ofthe polymer intercalant and the matrix polymer.

[0020] In accordance with a preferred embodiment of the presentinvention, intercalates are prepared by contacting a phyllosilicate witha monomeric onium ion spacing agent compound. To achieve the fulladvantage of the present invention, the onium ion should include atleast one long chain radical (C₆+) that may be aliphatic, straight orbranched chain, or aralkyl. Exemplary of such suitable C₆+ onium ionmolecules include primary, secondary, tertiary or quaternary ammoniumions, sulfonium ions, phosphonium ions, oxonium ions, or any ion of anelement in Groups V or VI of the periodic table of elements.

[0021] In accordance with an important feature of the preferredembodiment of the present invention, best results are achieved by mixingthe layered material with the onium ions, e.g., C₆+ onium ion spacingcoupling agent-reacted, in a concentration of at least about 2% byweight, preferably at least about 5% by weight onium ion compound, morepreferably at least about 10% by weight onium ion compound, and mostpreferably about 20% to about 50% by weight, based on the weight ofonium ion compound and carrier (e.g., water, with or without an organicsolvent for the onium ion compound) to achieve better sorption of theonium ion spacing agent compound between the platelets of the layeredmaterial. Regardless of the concentration of onium ion compound in theonium ion intercalating composition, the weight ratio of polymerintercalant:layered material should be at least 1:20, preferably atleast 1:10, more preferably at least 1:5, and most preferably about 1:4to achieve sufficient oligomer or polymer intercalation of polyolefinand maleic anhydride-modified polyolefin intercalants between adjacentinner surfaces of adjacent platelets of the layered material. Theoptional, preferred onium ion spacing agent compound ion-exchanged withand bonded to (or complexed with) the aluminosilicate platelets viaion-exchange causes surprisingly easy intercalation of the polyolefinoligomer or polymer intercalants.

[0022] Due to the low polarity of general polyolefin resins, acompatiblizer such as a maleic anhydride-modified polyolefin is neededto achieve good intercalation and exfoliation of apolyolefin-intercalated layered silicate material, such as amontmorillonite clay, in the matrix resin. However, the intercalationand exfoliation of the layered silicate material in a polyolefin matrixpolymer can also be achieved without a compatibilizer, such as a maleicanhydride-modified polyolefin if the polyolefin has sufficient polarity.In addition, the intercalation and exfoliation of the layered silicatematerial can be achieved by using a maleic anhydride-modified polyolefinas the matrix resin. For some polyolefins, such as ethylene vinylacetate (EVA), the polarity is high enough for the layered silicatematerial to be intercalated and exfoliated, without the need for themaleic anhydride-modified polyolefin. In this case, no additionalcompatibilizer is needed to form nancomposites.

[0023] The co-intercalation of the combination of a polyolefin and amaleic anhydride-modified polyolefin to form a concentrate intercalateor a concentrate exfoliate, in accordance with the preferred embodimentof the present invention, provides an intercalate or exfoliateconcentrate that can be added, particularly by direct compounding(mixing the intercalate directly into a matrix polymer melt, preferablya polyolefin matrix polymer melt that is the same as the intercalatedcombination of the polyolefin and maleic anhydride-modified polyolefin)of the intercalate with a matrix oligomer or matrix polymer that is acombination of the same polyolefin and the same maleicanhydride-modified polyolefin that were intercalated between adjacentplatelets of the layered silicate material. The co-intercalation of thepreferred combination to form a concentrate intercalate composition or aconcentrate exfoliate composition can also be formed through either asolution or emulsion intercalation process route. The intercalate and/orexfoliate concentrate, added to the matrix polymer, improved a number ofproperties of the matrix polymer, including tensile properties,dimensional stability, ductility, gas-impermeability, and the like.

DEFINITIONS

[0024] Whenever used in this Specification, the terms set forth shallhave the following meanings:

[0025] “Layered Material” shall mean an inorganic material, such as asmectite clay mineral, that is in the form of a plurality of adjacent,bound layers and has a thickness, for each layer, of about 3 Å to about50 Å, preferably about 10 Å.

[0026] “Platelets” shall mean individual layers of the Layered Material.

[0027] “Intercalate” or “Intercalated” shall mean a Layered Materialthat includes a polyolefin oligomer or polyolefin polymer and a maleicanhydride-modified polyolefin oligomer or polymer disposed betweenadjacent platelets of the Layered Material to increase the interlayerspacing between the adjacent platelets at least 3 Å, preferably at least5 Å, to an interlayer spacing, for example, of at least about 10 Å,preferably at least about 15 Å;

[0028] “Optional Coupling Agent-Treated” or “Optional CouplingAgent-Treatment” or “Optional Coupling Agent-Reacted” shall mean theoptional contact of a layered material with a coupling agent, e.g., asilane coupling agent, a titanate coupling agent, a zirconate couplingagent and/or an aluminate coupling agent to produce a condensationreaction between the coupling agent and —OH radicals at the edges of theplatelets of the Layered Material.

[0029] “Intercalation” shall mean a process for forming an Intercalate.

[0030] “Onium Ion Spacing Agent” or “Onium Ion Compound” shall mean anorganic compound that includes a positively charged atom selected fromthe group consisting of a nitrogen atom, a phosphorous atom, a sulfuratom or an oxygen atom, preferably a quaternary ammonium compound, andwhen dissolved in water and/or an organic solvent, an anion dissociatesfrom the onium ion spacing agent leaving an onium cation that canion-exchange with a silicate platelet exchangeable cation, e.g., Na⁺,Ca⁺², Li⁺, Mg⁺², or K⁺, thereby binding to the silicate platelet innersurface.

[0031] “Co-Intercalation” shall mean a process for forming anintercalate by intercalation of an oligomer or polymer of a polyolefin,e.g., polypropylene, and, at the same time or separately, intercalationof a maleic anhydride-modified polyolefin polymer, or intercalation of amaleic anhydride-modified polyolefin oligomer.

[0032] “Concentrate” shall mean an intercalate or exfoliate, formed bythe Co-Intercalation of a Layered Material to form a concentratecomprising 10-90% polyolefin oligomer or polymer, same as or differentthan the matrix polymer, and 10-90% polyolefin Intercalate or polyolefinexfoliate.

[0033] “Intercalating Carrier” shall mean a carrier comprising waterand/or an organic solvent used with the intercalant oligomers orpolymers to form an Intercalating Composition capable of achievingIntercalation of the polyolefin co-intercalants and, at the same time orseparately, intercalation of the oligomers or polymers between plateletsof the Layered Material.

[0034] “Intercalating Composition” or “Intercalant Composition” shallmean a composition comprising a Layered Material together with apolyolefin and/or a maleic anhydride-modified polyolefin, with orwithout an Intercalating Carrier.

[0035] “Exfoliate” or “Exfoliated” shall mean individual platelets of aCo-Intercalated Layered Material or tactoids or clusters of individualplatelets, e.g., 2-10 platelets, preferably 2-5 platelets, that aresmaller in total thickness than the non-exfoliated Layered Material,dispersed as individual platelets or tactoids throughout a carriermaterial, such as water, a polymer, an alcohol or glycol, or any otherorganic solvent, or throughout a matrix polymer.

[0036] “Exfoliation” shall mean a process for forming an Exfoliate froman Intercalate.

[0037] “Matrix Polymer” shall mean an oligomer or polymer, that theIntercalate or Exfoliate is dispersed within to improve the mechanicalstrength, thermal resistance, and/or the gas (O₂) impermeability of theMatrix Polymer, preferably a polyolefin homopolymer or polyolefincopolymer, particularly polyethylene, polypropylene or copolymersthereof.

SUMMARY OF THE INVENTION

[0038] In brief, the present invention is directed to intercalatedlayered materials prepared by intercalation of a polyolefin, preferablypolypropylene, and optionally a maleic anhydride-modified polyolefin,preferably a maleic anhydride-modified polypropylene oligomer orpolymer, between the planar layers of a swellable layered material, suchas a phyllosilicate, preferably a smectite clay, to form a concentrate.The concentrate can be subjected to substantial sheer to exfoliate amajority of the intercalate; preferably at least 80% by weight of theintercalated layered material is exfoliated into individual plateletsand/or tactoids of 2-5 platelet layers. After exfoliation, additionalmatrix polyolefin polymer can be added to avoid additional shear,thereby avoiding polymer degradation of the matrix polymer added to theconcentrate.

[0039] The present invention is directed to a method of preparingintercalated layered materials, prepared by intercalation of apolyolefin oligomer or polymer and optionally a maleicanhydride-modified polyolefin oligomer or polymer into the galleries ofthe layered material to form an intercalate concentrate composition thatprovides new and unexpected dispersibility throughout a matrix polymer,particularly a matrix oligomer or matrix polymer that is a combinationof polypropylene, and a maleic anhydride-modified polypropylene.

[0040] The present invention also is directed to the intercalates andexfoliates prepared from the intercalate or intercalate concentratecompositions. When the concentrate is mixed with a melt of thecombination of a polyolefin and a maleic anhydride-modified polyolefinmatrix oligomer or matrix polymer after shearing, (preferably the samepolymer as the predominant intercalant polymer), the layered materialsare unexpectedly easily dispersed throughout the matrix oligomers ormatrix polymers, without degradation by shearing of the added matrixpolymer.

[0041] The layered material is intercalated, preferably by firstcontacting the layered material with an onium ion spacing agent andsimultaneously or thereafter adding the melted polyolefin oligomerintercalant or melted polyolefin polymer intercalant to the oniumion-intercalated layered material, such as by direct compounding of thelayered material and the melted oligomer(s) or polymer(s) intercalant inan extruder, to intercalate the onium ion and melted polyolefinoligomer(s) or polymer(s) between adjacent phyllosilicate platelets andoptionally separate (exfoliate) the layered material into individualplatelets. The present invention also is directed to the intercalatesand exfoliates prepared from the intercalate or intercalate concentratecompositions. Melt compounding or solution/emulsion intercalationprocesses can be used to prepare the compositions.

[0042] Addition of the intercalate to a polymer melt enhances one ormore properties, such as strength, temperature resistance, dimensionalstability, ductility, and/or gas impermeability of the polymer; ormixing the intercalate with a carrier or solvent material maintainsand/or increases viscosity and thixotropy of the carrier material. Theintercalate is easily, homogeneously and uniformly dispersed throughouta matrix oligomer or matrix polymer combination of a polyolefin and amaleic anhydride-modified polyolefin and provides new and unexpectedstrength properties to non-polar matrix polymers by virtue of theunexpectedly homogeneous dispersibility of the co-intercalate and/orexfoliate throughout a low polarity or non-polar matrix oligomer orpolymer, particularly a combination of polypropylene and maleicanhydride-modified polypropylene.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] To form the intercalated and exfoliated materials of the presentinvention, the layered material, e.g., the phyllosilicate, should beintercalated with a polyolefin oligomer or polymer, preferablypolyethylene or polypropylene, and thereafter melt compounded with amatrix oligomer or matrix polymer combination of a polyolefin,preferably polyethylene or polypropylene, and with an oligomer orpolymer of a maleic anhydride-modified polyolefin, preferablypolyethylene or polypropylene.

[0044] In a preferred embodiment, the interlaminar spacing betweenadjacent platelets of a layered silicate material, e.g., aphyllosilicate, is expanded for easier co-intercalation by a firsttreatment with a coupling agent followed by intercalation andion-exchange of onium ions between the aluminosilicate platelets, priorto or simultaneously with intercalation of the polyolefin oligomer(s) orpolymer(s). It should be understood that the oligomer or polymerintercalant(s) can be intercalated between and complexed to the internalplatelet faces by other well known mechanisms, such as the dipole/dipole(direct intercalation of the oligomer or polymer) method disclosed inthis Assignee's U.S. Pat. Nos. 5,880,197 and 5,877,248, herebyincorporated by reference; and by the acidification technique—bysubstitution with hydrogen (ion-exchanging the interlayer cations withhydrogen by use of an acid or ion-exchange resin) as disclosed in theDeguchi U.S. Pat. No. 5,102,948, and in the Pinnavaia, et al. U.S. Pat.No. 5,853,886, both patents hereby incorporated by reference.

OPTIONAL ONIUM ION SPACING AGENT

[0045] The onium ion spacing agent is introduced into the layeredmaterial galleries in the form of a solid or liquid composition (neat oraqueous, with or without an organic solvent, e.g., an aliphatichydrocarbon, such as heptane to, if necessary, aid to dissolve the oniumion compound) having an onium ion spacing agent concentration sufficientto provide an onium ion concentration of about 5% to about 10% by weightof the clay (90-95% water) and the onium ion compound is dissolved inthe clay slurry water, preferably at a molar ratio of onium ions toexchangeable interlayer cations of at least about 0.25:1, morepreferably at least about 0.5: 1, most preferably at least about 1:1.The onium ion-intercalated clay then is separated from the water easily,since the clay is now hydrophobic, and dried in an oven to less than 5%water, preferably bone dry, before being compounded (co-intercalated)with the oligomers or polymers, for co-intercalation of the oligomers orpolymers and homogeneous platelet dispersion. The optional onium ionspacing agent compound can be added as a solid with the addition to thelayered material onium ion compound blend of preferably at least about20% by weight water, more preferably at least about 30% by weight wateror more, based on the dry weight of the layered material. Preferablyabout 30% to about 50% water, more preferably about 30% to about 40% byweight water, based on the dry weight of the layered material, isincluded in the onium ion intercalating composition, so that less wateris sorbed by the intercalate, thereby necessitating less drying energyafter onium ion intercalation.

[0046] The optional, but preferred onium ion spacing agent cationsintercalated via ion-exchange into the interlayer spaces betweenadjacent layered material platelets are primary, secondary, tertiary orquaternary onium ions having the following preferred structure:

[0047] wherein X=N, P, S, or O; and

[0048] wherein R₁, R₂, R₃ and R₄ are H or organic moieties, such aslinear or branched alkyl, aryl or aralkyl moieties having 1 to a bout 24carbon atoms.

[0049] The more preferred C₆+ onium ions are preferably quaternaryammonium ions having Formula 1, as follows:

[0050] Wherein R₁ is a long chain alkyl moiety ranging from C₆ to C₂₄,straight or branched chain, including mixtures of long chain moieties,i.e., C₆, C₈, C₁₀, C₁₂, C₁₄, C₁₆, C₁₈, C₂₀, C₂₂ and C₂₄, alone or in anycombination; and R₂, R₃ and R₄ are moieties, same or different, selectedfrom the group consisting of H, alkyl, benzyl, substituted benzyl, e.g.,straight or branched chain alkyl-substituted and halogen-substituted;ethoxylated or propoxylated alkyl; ethoxylated or propoxylated benzyl,e.g., 1-10 moles of ethoxylation or 1-10 moles of propoxylation.

[0051] Additional useful multi-charged spacing/coupling agents includefor example, tetra-, tri-, and di-onium species such as tetra-ammonium,tri-ammonium, and di-ammonium (primary, secondary, tertiary, andquaternary), -phosphonium, -oxonium, or -sulfonium derivatives ofaliphatic, aromatic or arylaliphatic amines, phosphines, esters,alcohols and sulfides. Illustrative of such materials are di-oniumcompounds of the formula:

R¹—X⁺—R—Y⁺

[0052] where X⁺ and Y⁺, same or different, are ammonium, sulfonium,phosphonium, or oxonium radicals such as

—NH(CH₃)₂ ⁺, —NH₂(CH₃)⁺, —N(CH₃)₃ ⁺,

—N(CH₃)₂(CH₂CH₃)⁺, —N(CH₃)(CH₂CH₃)₂ ⁺, —S(CH₃)₂ ⁺,

—S(CH₃)₂ ⁺, —P(CH₃)₃ ⁺, —NH₃ ⁺,

[0053] and the like; R is an organic spacing, backbone radical, straightor branched, preferably having from 2 to 24, more preferably 3 to 10carbon atoms, in a backbone organic spacing molecule covalently bondedat its ends to charged N⁺, P⁺, S⁺ and/or O⁺ cations and R¹ can behydrogen, or an alkyl radical of 1 to 22 carbon atoms, linear orbranched, preferably having at least 6 carbon atoms. Examples of Rinclude substituted or unsubstituted alkylene, cycloalkenylene,cycloalkylene, arylene, alkylarylene, either unsubstituted orsubstituted with amino, alkylamino, dialkylamino, nitro, azido, alkenyl,alkoxy, cycloalkyl, cycloalkenyl, alkanoyl, alkylthio, alkyl, aryloxy,arylalkylamino, alkylamino, arylamino, dialkylamino, diarylamino, aryl,alkylsufinyl, aryloxy, alkylsulfinyl, alkylsulfonyl, arylthio,arylsulfinyl, alkoxycarbonyl, arylsulfonyl, or alkylsilane. Examples ofR¹ include non-existent; H; alkyl having 1 to 22 carbon atoms, straightchain or branched; cycloalkenyl; cycloalkyl; aryl; alkylaryl, eitherunsubstituted or substituted or substituted with amino, alkylamino,dialkylamino, nitro, azido, alkenyl, alkoxy, cycloalkyl, cycloalkenyl,alkanoyl, alkylthio, alkyl, aryloxy, arylalkylamino, alkylamino,arylamino, dialkylamino, diarylamino, aryl, alkylsufinyl, aryloxy,alkylsulfinyl, alkylsulfonyl, arylthio, arylsulfinyl, alkoxycarbonyl,arylsulfonyl, or alkylsilane. Illustrative of useful R groups arealkylenes, such as methylene, ethylene, octylene, nonylene,tert-butylene, neopentylene, isopropylene, sec-butylene, dodecylene andthe like; alkenylenes such as 1-propenylene, 1-butenylene,1-pentenylene, 1-hexenylene, 1-heptenylene, 1-octenylene and the like;cycloalkenylenes such as cyclohexenylene, cyclopentenylene and the like;alkanoylalkylenes such as butanoyl octadecylene, pentanoyl nonadecylene,octanoyl pentadecylene, ethanoyl undecylene, propanoyl hexadecylene andthe like; alkylaminoalkylenes, such as methylamino octadecylene,ethylamino pentadecylene, butylamino nonadecylene and the like;dialkylaminoalkylene, such as dimethylamino octadecylene,methylethylamino nonadecylene and the like; arylaminoalkylenes such asphenylamino octadecylene, p-methylphenylamino nonadecylene and the like;diarylaminoalkylenes, such as diphenylamino pentadecylene,p-nitrophenyl-p′-methylphenylamino octadecylene and the like;alkylarylaminoalkylenes, such as 2-phenyl-4-methylamino pentadecyleneand the like; alkylsulfinylenes, alkylsulfonylenes, alkylthio, arylthio,arylsulfinylenes, and arylsulfonylenes such as butylthio octadecylene,neopentylthio pentadecylene, methylsulfinyl -nonadecylene,benzylsulfinyl pentadecylene, phenylsulfinyl octadecylene,propylthiooctadecylene, octylthio pentadecylene, nonylsulfonylnonadecylene, octylsulfonyl hexadecylene, methylthio nonadecylene,isopropylthio octadecylene, phenylsulfonyl pentadecylene, methylsulfonylnonadecylene, nonylthio pentadecylene, phenylthio octadecylene, ethyltiononadecylene, benzylthio undecylene, phenethylthio pentadecylene,sec-butylthio octadecylene, naphthylthio undecylene and the like;alkoxycarbonylalkylenes such as methoxycarbonylene, ethoxycarbonylene,butoxycarbonylene and the like; cycloalkylenes such as cyclohexylene,cyclopentylene, cyclooctylene, cycloheptylene and the like;alkoxyalkylenes such as methoxymethylene, ethoxymethylene,butoxymethylene, propoxyethylene, pentoxybutylene and the like;aryloxyalkylenes and aryloxyarylenes such as phenoxyphenylene,phenoxymethylene and the like; aryloryalkylenes such as phenoxydecylene,phenoxyoctylene and the like; arylalkylenes such as benzylene,phenthylene, 8-phenyloctylene, 10-phenyldecylene and the like;alkylarylenes such as 3-decylphenylene, 4-octylphenylene,4-nonylphenylene and the like; and polypropylene glycol and polyethyleneglycol substituents such as ethylene, propylene, butylene, phenylene,benzylene, tolylene, p-styrylene, p-phenylmethylene, octylene,dodecylene, octadecylene, methoxyethylene, moieties of the formula—C₃H₆COO—, —C₅H₁₀COO—, —C₇H₁₀COO—, —C₇H₁₄COO—, —C₉H₁₈COO—, —C₁₁H₂₂COO—,—C₁₃H₂₆COO—, —C₁₅H₃₀COO—, and —C₁₇H₃₄COO— and —C═C(CH₃)COOCH₂CH₂—, andthe like. Such tetra-, tri-, and di-ammonium, -sulfonium, -phosphonium,-oxonium; ammonium/sulfonium; ammonium/phosphonium; ammonium/oxonium;phosphonium/oxonium; sulfonium/oxonium; and sulfonium/phosphoniumradicals are well known in the art and can be derived from thecorresponding amines, phosphines, alcohols or ethers, and sulfides.

[0054] The preferred multi-charged spacing/coupling agent compounds aremulti-onium ion compounds that include at least two primary, secondary,tertiary or quaternary ammonium, phosphonium, sulfonium, and/or oxoniumions having Formula 2, as follows:

[0055] wherein R is an alkylene, aralkylene or substituted alkylenecharged atom spacing moiety, preferably ranging from C₃ to C₂₄, morepreferably about C₃ to C₆ for relatively high charge density (150milliequivalents/100 grams C.E.C. to 70 milliequivalents/100 gramsC.E.C.) layered materials; and preferably from C₆ to C₁₂ for medium tolow charge density (70 milliequivalents/100 grams C.E.C. to 30milliequivalents/100 grams C.E.C.) layered materials. R can be straightor branched chain, including mixtures of such moieties, i.e., C₄, C₅,C₆, C₇, C₈, C₉, C₁₀, C₁₁, C₁₂, C₁₃, C₁₄, C₁₅, C₁₆, C₁₇, C₁₈, C₁₉, C₂₀,C₂₁, C₂₂, C₂₃ and C₂₄, alone or in any combination; and R₁, R₂, R₃ andR₄ are moieties, same or different, selected from the group consistingof hydrogen, alkyl, aralkyl, benzyl, substituted benzyl, e.g., straightor branched chain alkyl-substituted and halogen-substituted; ethoxylatedor propoxylated alkyl; ethoxylated or propoxylated benzyl, e.g., 1-10moles of ethoxylation or 1-10 moles of propoxylation. Z¹ and Z², same ordifferent, may be non-existent, or may be any of the moieties describedfor R₁, R₂, R₃ or R₄. Also, one or both of Z¹ and Z² may include one ormore positively charged atoms or onium ion molecules.

[0056] Any swellable layered material that sufficiently ion-exchangeswith the onium ion spacing agent at the internal platelet faces toincrease the interlayer spacing between adjacent phyllosilicateplatelets at least about 3 Å, preferably at least about 5 Å, can be usedin the practice of this invention. Useful swellable layered materialsinclude phyllosilicates, such as smectite clayminerals, e.g.,montmorillonite, particularly sodium montmorillonite; magnesiummontmorillonite and/or calcium montmorillonite; nontronite; beidellite;volkonskoite; hectorite; saponite; sauconite; sobockite; stevensite;svinfordite; vermiculite; and the like. Other useful layered materialsinclude micaceous minerals, such as illite and mixed layeredillite/smectite minerals, such as rectorite, tarosovite, ledikite andadmixtures of illites with the clay minerals named above.

[0057] Preferred swellable layered materials are phyllosilicates of the2:1 type having a negative charge on the layers ranging from about 0. 15 to about 0.9 charges per formula unit and a commensurate number ofexchangeable metal cations in the interlayer spaces. Most preferredlayered materials are smectite clay minerals such as montmorillonite,nontronite, beidellite, volkonskoite, hectorite, saponite, sauconite,sobockite, stevensite, and svinfordite.

[0058] As used herein the “interlayer spacing” refers to the distancebetween the internal faces of the adjacent layers as they are assembledin the layered material before any delamination (exfoliation) takesplace. The preferred clay materials generally include interlayer cationssuch as Na⁺, Ca⁺², K⁺, Mg⁺², NH₄ ⁺ and the like, including mixturesthereof, particularly Na⁺.

[0059] The amount of onium ion spacing agent intercalated into theswellable layered materials, in order that the intercalated layeredmaterial platelet surfaces sufficiently complex or bond via ion-exchangeto the onium ion spacing agent molecules such that the layered materialmay be sufficiently spaced for easy intercalation of an oligomer orpolymer may vary substantially between about 2%, preferably at leastabout 10%, and up to about 80%, based on the dry weight of the layeredmaterial. In the preferred embodiments of the invention, amounts ofonium ion employed, with respect to the dry weight of layered materialbeing intercalated, will preferably range from about 8 grams of oniumion spacing agent compound: 100 grams of layered material (dry basis),preferably at least about 10 grams of onium ion spacing agent compound:100 grams of layered material to about 80-90 grams onium ion spacingagent compound: 100 grams of layered material. More preferred amountsare from about 20 grams of onium ion spacing agent compound: 100 gramsof layered material to about 60 grams of onium ion spacing agentcompound: 100 grams of layered material (dry basis).

[0060] The polyolefin oligomer or polymer intercalant, and optionally amaleic anhydride-modified polyolefin oligomer or polymer intercalant,may be introduced into (sorbed within) the interlayer spaces of thelayered material in a number of ways. In one method of intercalating theoligomer or polymer intercalants between adjacent platelets of thelayered material, the layered material is slurried in water, e.g., at5-20% by weight layered material and 80-95% by weight water, and anonium ion compound is dissolved in the water in which the layeredmaterial is slurried. If necessary, the onium ion compound can bedissolved first in an organic solvent, e.g., propanol. The layeredmaterial then is separated from the slurry water and dried prior tocompounding, preferably melt compounding, with the oligomer or polymerintercalants (or co-intercalants) for intercalation of the polyolefinand, optionally, the maleic anhydride-modified polyolefin oligomer orpolymer co-intercalant, to form the nanocomposite material in aconcentrated form in polyolefin and maleic anhydride-modified polyolefinmatrix oligomers or matrix polymers.

[0061] The intercalates and exfoliates can also be prepared throughsolution/emulsion processes. Optionally, the onium ion-intercalatedlayered material can be first intercalated with the polyolefin, prior toadding the matrix polymer, comprising both a polyolefin and a maleicanhydride-modified polyolefin or only the maleic anhydride-modifiedpolyolefin, and then intercalated with the maleic anhydride-modifiedpolyolefin from the matrix polymer, since regardless of the amount ofpolyolefin initially intercalated, some maleic anhydride-modifiedpolyolefin will also be intercalated into the layered material from thematrix polymer. Optionally, the onium ion-intercalated layered materialcan be first intercalated with the maleic anhydride-modified pololefin,prior to adding the matrix polymer, comprising both a polyolefin and amaleic anhydride-modified polyolefin or only the polyolefin. In thiscase, it is preferred to limit the layered silicate material: maleicanhydride-modified polyolefin weight ratio to less than 1:2 to ensure alow (≦10% by weight) concentration of maelic anhydride-modifiedpolyolefin in the final nanocomposite. A layered silicate materialintercalated with only the maleic anhydride-modified polyolefin (nopolyolefin) can be easily dispersed into a polyolefin matrix resin(oligomer or polymer) to co-intercalate the polyolefin and form thenanocomposite.

[0062] The polyolefins can be intercalated into layered silicatematerials by the emulsion process (as opposed to the melt compoundingprocess) by vigorously mixing the polyolefin and/or the maleicanhydride-modified polyolefin with an emulsifier, such as non-ionic,cationic and/or anionic emulsifier. Cationic emulsifiers are preferredsimply due to their good compatibility with montmorillonite clays. Somecationic emulsifiers, such as octadecyl amine, are most preferred, sincethey also function as montmorillonite surface modifiers (onium ions). Ingeneral, the low molecular weight, highly volatile emulsifiers are notpreferred in the invention, due to a lessening of the finalnanocomposite properties.

[0063] The coupling agent may be reacted with the layered material,preferably in an amount of about 2-4% by weight, based on the weight ofthe layered material, before or after (or simultaneously with) the oniumion-exchange intercalation. Preferred reaction conditions (which mayvary considerably) include a temperature of about 70-75° C. , a pH ofabout 3-5, to completion of the reaction. The coupling agent reactioncan be performed in a slurry media or dry blending conditions. Theselower reaction temperatures are preferred to allow the coupling agent toreact at edge hydroxy groups more homogeneously over the entire layeredmaterial edges. In addition, the coupling agent may be introduced to thelayered silicate in situ during the polymer melt compounding process. Ina preferred method of intercalating the polymer, the coupling agentreacted and onium ion-treated layered material is intimately mixed withthe polymer, e.g., by extrusion or pug milling, to form an intercalatingcomposition comprising the coupling agent-reacted/onium ion-intercalatedlayered material and the intercalant polymer. In a preferred method ofintercalating the oligomer or polymer intercalant, a coupling-agentreacted and onium ion-exchanged layered material is intimately mixedwith a melt of the polymer co-intercalants, e.g., by extrusion or pugmilling, to form an intercalating composition comprising a couplingagent-reacted/onium ion-intercalated layered material and a melt of theco-intercalant polyolefin and maleic anhydride-modified matrix oligomersor matrix polymers to form a co-intercalated concentrate composition forlater dilution by the addition of matrix oligomers or matrix polymers toform the nanocomposite.

[0064] The coupling agent-treated layered material and onium ionintercalating composition preferably contains at least about 5% byweight, more preferably at least about 10% by weight onium ion compound,based on the dry weight of the coupling agent-treated layered material,so that the resulting onium ion-intercalated (ion-exchanged) layeredmaterial has interior platelet surfaces that are sufficientlyhydrophobic and sufficiently spaced for co-intercalation of thepolyolefin and maleic anhydride-modified polyolefin oligomers orpolymers. The amount of the coupling agent, when used, should be atleast 0.1% by weight, based on the dry weight of the layered material,preferably in the range of 0.5% to 60% by weight, based on the dryweight of the layered material. The onium ion carrier (preferably water,with or without an organic solvent) can be added by first solubilizingor dispersing the onium ion compound in the carrier; or a dry onium ioncompound and relatively dry coupling agent-treated phyllosilicate(preferably containing at least about 4% by weight water) can be blendedand the intercalating carrier added to the blend, or to thephyllosilicate prior to adding the dry onium ion. When intercalating thephyllosilicate with onium ions in slurry form (e.g., 900 pounds water,100 pounds phyllosilicate, 100 pounds onium ion compound), the amount ofwater can vary substantially, e.g., from about 4% by weight, preferablyfrom a minimum of at least about 30% by weight water, with no upperlimit to the amount of water in the intercalating composition (thephyllosilicate intercalate is easily separated from the intercalatingcomposition due to its hydrophobicity after onium ion treatment).

[0065] Alternatively, the onium ion intercalating carrier, e.g., water,with or without an organic solvent, can be added directly to thecoupling agent-treated phyllosilicate prior to adding the onium ioncompound, either dry or in solution. Ion-exchange of the onium ioncompound molecules may be performed by exposing the couplingagent-treated layered material to a dry or liquid onium ion compound inthe onium ion intercalating composition containing at least about 2% byweight, preferably at least about 5% by weight onium ion compound, morepreferably at least about 10% onium ion compound, based on the dryweight of the layered material.

[0066] In accordance with another method of intercalating the onium ionsand the polyolefin oligomer(s) or polymer(s) between the platelets ofthe coupling agent-reacted layered material, the layered material,preferably containing at least about 4% by weight water, more preferablyabout 10% to about 15% by weight water, is blended with water and/ororganic solvent solution of an onium ion spacing agent compound in aratio sufficient to provide at least about 5% by weight, preferably atleast about 10% by weight onium ion compound, based on the dry weight ofthe layered material. The onium ion compound can be intercalated andion-exchanged into a coupling agent-reacted layered materialsimultaneously with onium ion spacing agent contact with the layeredmaterial and simultaneously with the intercalation of the preferredpolyolefin intercalant (and optionally a maleic anhydride-modifiedco-intercalant) oligomer(s) or polymer(s); or, the intercalantoligomer(s) or polymer(s) may be intercalated without or after couplingagent-reaction and intercalation of the onium ion spacing agent. Inpreferred embodiment, the dry onium ion-intercalated clay is extrudedwith a melt of the intercalant oligomer(s) or polymer(s) for directcompounding, with intercalation of the intercalant oligomer(s) orpolymer(s) melt into the layered material with or without the couplingagent-reaction.

[0067] In accordance with a preferred embodiment of the presentinvention, the coupling agent-reacted/onium ion-intercalated(ion-exchanged) layered material can be intercalated with oligomer orpolymer by direct melt compounding in an extruder and then theintercalate is dispersed into a combination of a melt-processible,preferably polyolefin, matrix oligomer or polymer, and amelt-processible maleic anhydride-modified oligomer or polymer, to formthe nanocomposite. The matrix oligomers or matrix polymers for use inthis embodiment of the process of this invention comprise a vinylpolymer or copolymer, particularly a polypropylene homopolymer having amelt flow index of preferably about 0.5 to about 60, more preferablyabout 5-10. The matrix polymer is added to the concentrate ofco-intercalated layered material without extrusion of the added matrixpolymer, after extruding the layered material with a melt of thepolyolefin and maleic anhydride-modified polyolefin to form thenanocomposite concentrate in an extruder. The preferred matrixpolyolefin oligomer or polymer preferably includes from at least about10 to about 100 recurring monomeric units. In the most preferredembodiments of this invention, the number of recurring units is suchthat the matrix polymer has a melt index of from about 0.01 to about 12grams per 10 minutes at the processing temperature.

[0068] The most preferred thermoplastic homopolymers and copolymermatrix polymers for forming nanocomposites with the couplingagent-reacted onium ion/polymer co-intercalated layered materials of thepresent invention are polymers formed by polymerization ofalpha-beta-unsaturated monomers of the formula:

R²R³C═CH₂

[0069] wherein:

[0070] R² and R³ are the same or different and are cyano, phenyl,carboxy, alkylester, halo, alkyl, or alkyl substituted with one or morechloro or fluoro, or hydrogen atoms. Illustrative of such preferredhomopolymers and copolymers are homopolymers and copolymers of ethylene,propylene, vinyl alcohol, acrylonitrile, vinylidene chloride, esters ofacrylic acid, esters of in ethacrylic acid, chlorotrifluoroethylene,vinyl chloride and the like. Preferred are poly(propylene), propylenecopolymers, poly(ethylene) and ethylene copolymers. More preferred arehomopolymers of poly(ethylene) and poly(propylene), and block and randomcopolymers thereof, especially polypropylene.

[0071] The following polyolefins and olefin copolymers are all useful asnon-polar polyolefin and maleic anhydride-modified polyolefinintercalants, and as matrix polymers in accordance with the presentinvention.

[0072] Polyolefin homopolymers, including high-modulus homopolymers,contain only the olefin monomer in the polymer chain. The homopolymerprovides stiffness and toughness but exhibits low impact strength at lowtemperatures, and clarity is too low for some applications. All threetypes of polyolefins, e.g., polyethylene, crystalline, amorphous, andelastomeric, are suitable as intercalants in accordance with the presentinvention. Polyolefin copolymers, such as ethylene-vinyl acetate (EVA),poly(4-methylpentene-1), and ethylene/α-olefin copolymers, contain oneor more different types of monomers in the polymer chain. Randomcopolymers are used in applications requiring higher clarity or a lowermelting point, and impact copolymers are used in automotive and otherapplications that require high impact resistance at low temperatures.Thermoplastic olefins and thermoplastic vulcanizates provide elastomericproperties for automotive, medical, and other applications.

[0073] Preferred polyolefins, and their densities, are shown in Table I:TABLE I Macromolecular Density range Polyolefin type classification(g/cm³) Low-density polyethylene (LDPE) Homopolymer 0.910-0.925Medium-density polyethylene Homopolymer 0.926-0.940 (MDPE) Linearlow-density polyethylene Copolymer 0.910-0.940 (LLDPE) Very-low-densitypolyethylene Copolymer 0.890-0.915 (VLDPE) High-density polyethyleneCopolymer 0.941-0.959 (HDPE) High-density polyethylene Homopolymer 0.960& higher (HDPE) HMW polyethylene (HMWPE) Homopolymer 0.947-0.955 UHMWpolyethylene (UHMWPE) Homopolymer 0.940 Polypropylene Homopolymer0.904-0.906 Ethylene-propylene copolymer Copolymer 0.904-0.907Polybutene-1 Homopolymer 0.910 Poly(4-methyl pentene-1) homopolymer0.830

[0074] Random and block copolymers are recently developed copolymers inwhich particles of ethylene propylene rubber are distributed through arandom copolymer polypropylene matrix. Random block copolymers displayhigh stiffness and toughness, and the added softness of the randomcopolymer matrix results in less stress whitening than in impactcopolymers. Random copolymers are produced by adding the comonomer,ethylene or, less commonly, 1-butene or 1-hexene, to the reactor duringthe polymerization reaction. The comonomer substitutes for propylene inthe growing polymer chain. Insertions are randomly or statisticallydistributed along the chain and can consist of single monomers, ormultiple monomers (two or more sequential ethylene molecules along thepolymer chain). Random copolymers generally contain 1-7 wt. % ethylene,with 75% single and 25% multiple insertions. In practice, depending onthe catalyst, polymerization conditions, and the reactivity of thecomonomer compared to propylene, random copolymers can become somewhatblocky, with some regions of the polymer chain containing onlypolypropylene units and other regions containing only comonomer.

[0075] The structure of random copolymers is similar to isotacticpolypropylene, but the regular, repeating arrangement of atoms israndomly disrupted by the presence of comonomer units. The effect issimilar to that of increasing atacticity. Crystallinity is reduced, andmobility of the polymer chain is increased due to less stearicinteraction of the pendant methyl groups of polypropylene.

[0076] Plastomers are very low density (<0.880 g/cc) copolymers ofethylene and an olefin (such as ethylene-butene) produced usingmetallocene catalysts. Due to the single polymerization site onmetallocene catalysts, comonomer can be inserted uniformly, producing ahomogeneous copolymer with both elastomeric and plastic characteristics.They have a narrow molecular weight distribution and more long-chainbranching.

[0077] Impact copolymers containing ethylene-propylene rubber are alsouseful as the matrix polymer and polymer intercalate in accordance withthe present invention. Homopolymer formed in the first reactor istransferred to a second reactor, where copolymerization with ethylene isperformed to produce ethylene-propylene rubber within the polypropylenematrix.

[0078] Other suitable polyolefins include poly(4-methyl(pentene-1), andelastomeric polyolefins, such as (1) poly(transisoprene); (2)poly(choloroprene); (3) poly(1,2 butadiene); (4)poly(styrene-co-butadiene); (5) nitrile rubber; (6) butyl rubber; (7)ethylene-propylene rubber (EPR); (8) ethylene-propylene-diene monomerrubber (EPDM), and the like.

[0079] Thermoplastic olefins (TPOs) are a blend of two polymer systems,with usually polypropylene or polyvinyl chloride as the crystallinematrix and ethylene propylene (EP) rubber, ethylene propylene dienemonomer (EPDM), or metallocene-produced plastomers (i.e.ethylene-octene, ethylene-butene) as the elastomeric phase. Thedistinction between impact copolymers and thermoplastic olefins is notwell defined; usually elastomer levels over about 20% are referred to asthermoplastic olefins. TPOs can be made by blending EPDM or EP rubberwith polypropylene in a batch mixer or by forming the EP rubber phaseduring propylene polymerization in the reactor. Examples of othersuitable blends are shown in Table II: TABLE II HMW PP/PP HMW HDPE/HDPEPP/LDPE HMW MDPE/MDPE PP/HDPE HMW HDPE/LLDPE PP/EPDM PB-1/PP PP/PIB/LDPEPB-1/HDPE PP/EPDM/HDPE Polyolefins/S-EB-S/engineering thermoplasticsPP-EP/HDPE PP/S-EB-S/PBT PP/EPR or EBR/LDPE or EVA PP/S-EB-S/polyamidesHDPE/EPR or EBR/LDPE or EVA Polyolefins/S-EP-S/engineeringthermoplastics PB-1/EPR or EBR/LDPE or EVAPolyolefin/S-EP-S/polyphenylene ether LDPE/LLDPEPolyolefin/S-EP-S/thermoplastic polyurethane LDPE/LLDPE/EVA

[0080] Depending on the formulation, thermoplastic olefins can beflexible or rigid; flexural moduli can range from 70 MPa (10,000 psi) to2000 MPa (300,000 psi). Typical properties include high heat resistance,high melt flow, and superior low temperature impact resistance.Thermoplastic olefins can maintain ductile impact behavior at −34° C.(−30° F.).

[0081] In testing of equivalent 70/30 polypropylene/elastomer blends,plastomers doubled the weld-line strength and raised the melt index byup to 50% compared to EPDM, with a superior balance of flow andlow-temperature impact properties. Plastomers maintained ductilebehavior at −34° C. (-30° F.) with homopolymers of 4-35 g/10 minute meltflow indices, while EPDM and ethylene propylene monomer (EPM) blendswere brittle with polypropylenes of 20 g/10 minute melt indices.

[0082] Thermoplastic vulcanizates (TPV), a type of thermoplasticelastomer, are a blend of a thermoplastic, usually polypropylene, and arubber, similar to a thermoplastic olefin; however, the rubber phase inthermoplastic vulcanizates is crosslinked or vulcanized. EPDM is mostcommonly used as the elastomeric phase; other elastomers used include EPrubber, butyl rubber, and natural rubber. The elastomeric phase,consisting of small, 1-2 tm rubber particles, is dispersed in thecontinuous polypropylene matrix. Elastomeric performance properties ofthe TPV are determined by the crosslinking of the elastomeric phase,while the polypropylene phase provides for melt processability. TPVs canbe fully or partially crosslinked.

[0083] Other suitable polyolefin include poly(cycloolefin) homopolymers,such as cyclobutene, cyclopentene, and norbornene, and cycloolefincopolymers, such as those formed by co-polymerizing a cycloolefinhomopolymer with ethylene, propylene, butylene or an (x-olefin toproduce thermoplastic amorphous co-polymers.

[0084] The matrix polymer of the present invention may include variousoptional components which are additives commonly employed with polymericcompositions. Such optional components include nucleating agents,fillers, plasticizers, impact modifiers, chain extenders, plasticizers,colorants, mold release lubricants, antistatic agents, pigments, fireretardants, and the like. These optional components and appropriateamounts are well known to those skilled in the art.

[0085] The amount of intercalated layered material included may varywidely. It is preferred that the intercalate or platelet loading be lessthan about 10% by weight of the polymeric composition. Intercalate orplatelet particle loadings within the range of about 0.01% to about 40%by weight, preferably about 0.05% to about 20%, more preferably about0.5% to about 10% of the total weight of the composition.

[0086] In accordance with an important feature of the present invention,the intercalate and/or platelet/carrier compositions of the presentinvention can be manufactured in a concentrated form, e.g., as aconcentrate, e.g., having about 10-90%, preferably about 20-80%intercalate and/or exfoliated platelets of layered material and about10-90%, preferably about 20-80% matrix polymer. The concentrate can bedispersed in the matrix polymer and optionally exfoliated, before theaddition of more matrix polymer to prevent degradation of the addedmatrix polymer by avoiding matrix polymer—degrading shearing.

[0087] When shear is employed for exfoliation, any method which can beused to apply a shear to the intercalate/matrix polymer nanocompositecomposition can be used to exfoliate the platelets in the concentratecomposition. The shearing action can be provided by any appropriatemethod, as for example by mechanical means, by thermal shock, bypressure alteration, or by ultrasonics, all known in the art. Inparticularly useful procedures, the concentrate composition is shearedby mechanical methods in which the intercalate concentrate, with orwithout the carrier or solvent, is sheared by use of mechanical means,such as stirrers, Banbury® type mixers, Brabender® type mixers, longcontinuous mixers, and extruders. Another procedure employs thermalshock in which shearing is achieved by alternatively raising or loweringthe temperature of the concentrate composition causing thermalexpansions and resulting in internal stresses which cause the shear. Instill other procedures, shear is achieved by sudden pressure changes inpressure alteration methods; by ultrasonic techniques in whichcavitation or resonant vibrations which cause portions of theconcentrate composition to vibrate or to be excited at different phasesand thus subjected to shear. These methods of shearing are merelyrepresentative of useful methods, and any method known in the art forshearing intercalates concentrate compositions may be used.

[0088] Mechanical shearing methods may be employed such as by extrusion,injection molding machines, Banbury® type mixers, Brabender® type mixersand the like. Shearing also can be achieved by introducing the layeredmaterial and co-intercalant oligomer(s) or polymer(s) at one end of anextruder (single or double screw) and receiving the sheared material atthe other end of the extruder. The temperature of the layeredmaterial/intercalant oligomer or polymer composition, the length of theextruder, residence time of the composition in the extruder and thedesign of the extruder (single screw, twin screw, number of flights perunit length, channel depth, flight clearance, mixing zone, etc.) areseveral variables which control the amount of shear to be applied to theconcentrate composition for exfoliation, prior to adding additionalmatrix oligomer or polymer.

[0089] In accordance with an important feature of the present invention,it has been found that the layered material can be intercalated withnon-polar polymer co-intercalants by direct compounding, i.e., by mixingthe layered material, e.g., smectite clay, directly with a non-polarpolyolefin oligomer or polymer and, optionally a maleicanhydride-modified oligomer or polymer (together or separately) in anextruder to make the co-intercalated clay without significantexfoliation of the clay platelets. The resulting intercalate concentratecan be extruded into a homogeneous nanocomposite concentrate withunexpectedly homogenous dispersion of the intercalate, and afteraddition of a combination of a polyolefin matrix oligomer or polymer anda maleic anhydride-modified polyolefin matrix oligomer or polymer, thenanocomposite has exceptional strength characteristics. The intercalateconcentrate dispersed within the matrix oligomers or matrix polymers isa combination of exfoliated individual platelets and multi-layertactoids dispersed in the matrix polymers. The tactoids have thethickness of at least two individual platelet layers plus one to fivemonolayer thicknesses of co-intercalated polyolefin and maleicanhydride-modified polyolefin intercalants, and include small multiplesor aggregates of platelets, in a coplanar aggregate, having oligomer orpolymer co-intercalants bonded or complexed or ion-exchanged to theplatelet surface(s).

[0090] Molding compositions comprising the combination of MA-PP and PPmatrix oligomers or matrix polymers containing a desired loading of theintercalates of the present invention, and/or individual plateletsobtained from exfoliation of the intercalates manufactured according tothe present invention, are outstandingly suitable for the production ofsheets, films and panels having valuable properties. Such sheets, filmsand panels may be shaped by conventional processes, such as vacuumprocessing or by hot pressing to form useful objects. The sheets andpanels according to the invention are also suitable as coating materialsfor other materials comprising, for example, wood, glass, ceramic, metalor other plastics, and outstanding strengths can be achieved usingconventional adhesion promoters, for example, those based on vinylresins. The sheets, films and panels can be laminated to other plasticfilms, sheets or panels and this is preferably effected by co-extrusion,the sheets being bonded in the molten state. The surfaces of the sheets,films and panels, including those in the embossed form, can be improvedor finished by conventional methods, for example by lacquering or by theapplication of protective films.

[0091] The nanocomposites of the present invention are also useful forfabrication of extruded films and film laminates, as for example, filmsfor use in food packaging. Such films can be fabricated usingconventional film extrusion techniques. The films are preferably fromabout 10 to about 100 microns, more preferably from about 20 to about100 microns and most preferably from about 25 to about 75 microns inthickness.

[0092] The homogeneously distributed intercalate, and/or exfoliatedplatelets thereof, which has been intercalated in accordance with thepresent invention, to form an intercalate concentrate, is then combinedwith pristine (non-sheared) matrix oligomers or matrix polymers (e.g.,MA-PP and PP) to form the preferred embodiment of the nanocompositecompositions of the present invention. The nanocomposite compositionscan be formed into a film by suitable film-forming methods. Typically,the composition is melted and forced through a film forming die afteroligomer or polymer intercalation and melt compounding. The film of thenanocomposite may go through sequential steps to cause the intercalateand/or exfoliated platelets thereof to be further oriented so the majorplanes through the intercalates and/or platelets thereof aresubstantially parallel to the major plane through the film. One methodto accomplish this is to biaxially stretch the film. For example, thefilm is stretched in the axial or machine direction by tension rollerspulling the film as it is extruded from the die. The film issimultaneously stretched in the transverse direction by clamping theedges of the film and drawing them apart. Alternatively, the film isstretched in the transverse direction by using a tubular film die andblowing the film up as it passes from the tubular film die. The filmsmay exhibit one or more of the following benefits in addition todecreased permeability to gases, particularly O₂: increased modulus;increased wet strength; increased dimensional stability; and decreasedmoisture adsorption.

[0093] The nanocomposite intercalate composition may containconventional additives such as UV stabilizers, flame, retardants,antioxidants, colorants, nucleating agents and plasticizers inconventional amounts.

EXAMPLES Example 1

[0094] Example 1 demonstrates the formation of silane-treated nanomerA137-ODA-CWC.

[0095] One hundred grams of Na-montmorillonite clay (PGW) commerciallyavailable from Nanocor, Inc. (Arlington Heights, Ill.) was dispersed in3 liters of de-ionized water by mechanical paddle mixer or colloidalmill. The clay dispersion was heated to 75˜80° C. 37.8 g ofoctadecyl-amine, available from Akzo Nobel, was mixed with 70 ml 2 N HClin 1 liter 75˜80° C. de-ionized water. The amine-HCl solution wasintroduced into the clay dispersion, followed by vigorous mixing. Themixture was adjusted to pH 3˜4 by acetic acid, and maintained at 75˜80°C. for about 30 minutes. After thorough washing with de-ionized water,the octadecyl-ammonium treated sodium montmorillonite clay was collectedby filtration. The filter cake was re-dispersed into 3 liters of 75˜80°C. water.

[0096] In a separate container, 2 g octyltriethoxysilane (A137) wasdissolved in 40 g 9:1 (w/w) blend of iso-propanol and de-ionized water.The silane solution was stirred for 1 hour and then added to thedispersed clay slurry. After mixing 20 minutes, the solid was collectedby filtration and placed into a 75˜80° C. oven to dry followed byparticle size reduction. The filter cake also can be freeze-dried. Thedried material has a d001 of 22 Å as measured by X-ray diffraction andwas coded as A137-ODA-CWC.

Example 2

[0097] The procedure of example 1 was repeated to produce asilane-treated organoclay except that octyltriethoxysilane was replacedby 3-aminopropyltriethoxysilane (A1100). The dried material has a d001of 22 Å as measured by X-ray diffraction and was coded as A1100-ODA-CWC.

Example 3

[0098] Example 3 demonstrates the formation and properties of apolypropylene (PP) homopolymer nanocomposite with a silane-treated andonium ion-treated nanomer through a direct melt compounding method, andabout 2.13% by weight maleic anhydride-modified polypropylene (MA-PP),based on the total weight of polypropylene intercalants.

[0099] Six parts of A1100-ODA-CWC was incorporated into 92 parts ofpolypropylene and 2 parts of maleic anhydride-modified polypropylene(MA-PP) using a twin screw extruder at 180-190° C. The presence of MA-PPhelps to improve the adhesion between the organoclay and thepolypropylene matrix polymer. The resulting pellets were injectionmolded into testing bars. X-ray diffraction shows the treated clay has awell ordered intercalation structure with a d001 of 29 Å. Physicalproperties of the thus-formed specimens were measured, and the resultsare shown in Table 1.

Example 4

[0100] Example 4 demonstrates the formation and properties of a PPnanocomposite with onium ion-intercalated clay (ODA-CWC nanomer—nosilane treatment) and about 2.13% by weight MA-PP, as shown in Example3, through a direct melt compounding method.

[0101] Six parts of ODA-CWC was incorporated into 92 parts ofpolypropylene and 2parts of maleic anhydride-modified polypropylene(MA-PP) using a twin screw extruder at 180-190° C. The presence of MA-PPhelps to improve the adhesion between the organoclay and thepolypropylene matrix polymer. The resulting pellets were injectionmolded into testing bars. X-ray diffraction shows the treated clay has awell ordered intercalation structure with a d001 of 28 Å.

[0102] Physical properties of the thus-formed specimens were measured,and the results are shown in Table 1.

Example 5

[0103] Example 5 demonstrates the in situ formation of silane-treatedonium ion-intercalated nanomer with the later addition of a silanecoupling agent in the extrusion process.

[0104] The procedure of Example 4 was repeated, with the exception that0.09 parts of silane A1100 was added during extrusion. The resultingnanocomposite has a d001 of 29 Å. The physical properties of the testingbars are shown in Table 1. In the case of Example 4 and Example 5, thepresence of silane will improve the interaction between the oniumion-intercalated clay and the polypropylene matrix polymer. As a result,both approaches give improved mechanical properties compared with normalODA-CWC clay (Example 4).

Example 6

[0105] Example 6 demonstrates the preparation of a polypropylene matrixpolymer/nanomer master batch, or concentrate, by using thesilane-treated nanomers, and the properties of the subsequentnanocomposites.

[0106] Seventy parts of ODA-CWC was mixed with 30 parts of MA-PP in amixing bowl at 180° C. for 5 minutes to make a master batch concentratecontaining about 43% by weight MA-PP and about 57% by weight oniumion-intercalated clay (organoclay). The resulting concentratecomposition (ODA-CWC-MA-PP) was chopped down into powder using agrinder. 8.6 parts of ODA-CWC-MA-PP composition was mixed with matrixpolymer comprising 89.4 parts of polypropylene and 2 parts of MA-PP(2.2% MA-PP) in a low shear, twin screw extruder (Leistrich 27 mm twinscrew compounder with L/D =36:1) at 180-190° C. The resulting pelletswere injection molded into testing bars. The nanocomposite has a d001 of29 Å. Physical properties of the thus-formed specimens were measured,and the results are shown in Table 1.

Example 7

[0107] Example 7 demonstrates the preparation of a polypropylene matrixpolymer/nanomer master batch, or concentrate, by using thesilane-treated nanomers, and the properties of the subsequentnanocomposites.

[0108] The procedure of Example 6 was repeated, except that ODA-CWC wasreplaced by A1100-ODA-CWC. The nanocomposite has a d001 of 29 Å.

Example 8

[0109] Example 8 demonstrates the preparation of a polypropylene matrixpolymer/nanomer master batch, or concentrate, by using the conventionalnanomer and silane coupling agent through a mixing device, and theproperties of the subsequent nanocomposites.

[0110] The procedure of Example 6 was repeated, except that 0.009 partsof A1100 (3-aminopropyltriethoxysilane) was added during extrusion. Thethus-formed nanocomposite has a d001 of 30 Å. In Examples 6-8, since theclays were pre-mixed in MA-PP matrix polymer, it is easier for the clayparticles to disperse homogeneously within the polypropylene matrixpolymer. As a result, better dispersion and improved mechanicalproperties are obtained by this master batch approach. In addition,silane treatment also improves the interaction between clay and thematrix polymer; and silane-treated clay (Examples 7 and 8) shows bettermechanical properties, especially tensile strength and heat distortiontemperature, compared with non-silane treated clay (Example 6). TABLE 1Mechanical Properties of PP, and PP-Clay Nanocomposites. Tensile TensileFlexural Flexural Processing Strength Modulus Strength Modulus NotchedIzod HDT Method Filler (Mpa) (GPa) (Mpa) (Gpa) Impact (ft-lb/in) (° C.)Neat PP Direct melt None 29.6 1.3 37.6 1.3 0.5  92 Montell compoundingProfax 6523 Example 3 Direct melt A1100- 32.7 1.8 46.5 1.7 0.6 104compounding ODA- CWC Example 4 Direct melt ODA- 33.2 1.7 46.3 1.6 0.5103 compounding CWC Example 5 Direct melt ODA- 32.9 2.0 48.3 1.8 0.6 107compounding CWC* Example 6 Master ODA- 35 1.8 48.8 2.0 0.6 100 batch CWCExample 7 Master A1100- 36.3 1.9 50.9 2.0 0.6 108 batch ODA- CWC Example8 Master ODA- 35.4 2.0 51.2 2.1 0.6 109 batch CWC*

Examples 9-13

[0111] Examples 9-13 demonstrate the importance of the nanocompositeperformance properties on the MA contents and molecular weights of theMA-PP in the nanocomposite formulations. The treated montmorillonite wasprepared under the same conditions as described in Example 2 andnanocomposites were processed according to Examples 6-8. The resultsindicate that the MA-PP with high molecular weight and moderate MAcontent (1-2%) is the most suitable compatibilizer to increase themechanical properties of nanocomposites. Examples 9 10 11 12 13 A1100-6% 6% 6% 6% 6% ODA-CWC Homo 89% 89% 89% 89% 89% PP 6523 MA-PP 5% 5% 5%5% 5% MW of low* medium* high* super high* high* MA-PP MA content 6% 2%1.5% 1% 0.34% Tensile 1738 2315 2681 2804 1867 modulus (MPa) Flexural1696 1846 1966 2043 1738 modulus (Mpa) HDT (° C.) 97 100.7 108.3 114.2107.0

Example 14

[0112] Example 14 describes the formation of an intercalate concentratethrough an emulsion process. MA-PP emulsions are commercially availablefrom manufacturers such as MICHELMAN, INC. and Chemcor. A product fromMICHELMAN, Michem® Emulsion 32225 is an emulsion of MA-PP G3015 fromEastman Chemical. Emulsion 32225 was incorporated into the Al100-ODA-CWC reaction process as described in Examples 1 and 2. Theintercalate concentrate was nearly identical in properties to theconcentrate prepared from melt processing. In addition, thenanocomposite prepared from the intercalate through the emulsion processhas comparable performance properties to the data of Example 10.

[0113] Relatively low loadings, e.g., 1-10% by weight, preferably about4% to about 6% by weight, of nanomers can achieve significant increasesin the strength of polyolefin polymers. In accordance with the presentinvention, it has been found that such low loadings of nanomers areparticularly effective in polyolefin matrix polymers that contain asmall percentage of maleic anhydride-modified polyolefin, preferablypolypropylene, e.g., 0.5% to 10%, preferably 1-6% by weight, based onthe total weight of polyolefin and maleic anhydride-modified polyolefinmatrix polymers. In accordance with one embodiment of the presentinvention, the nanomer is formed by intercalating a smectite clay, e.g.,sodium montmorillonite or calcium montmorillonite clay, with an oniumion first, and then intercalating the resulting organoclay with the sameblend of polyolefin/maleic anhydride-modified polyolefin as sued for thematrix polymer.

[0114] In the collection of following data, the nanomer was made byforming an organoclay (1.30P) from sodium montmorillonite clay bycontacting the clay with octadecylamine (ODA) and thereafterintercalating the organoclay with a blend of about 2% by weight MA-PPand 98% by weight PP homopolymer. This blend (2% MA-PP/98% PP) isintercalated into the organoclay, and the same blend is used as thematrix polymer of the resulting nanocomposite. It should be understoodthat while it is preferred to intercalate the onium ion-intercalatedclay with a polyolefin that includes a portion, e.g., 0.5-2% by weight,maleic anhydride-modified polyolefin, the nanomer can be made first byintercalating the onium ion-intercalated clay with any polyolefin orblend of polyolefins, so long as the matrix polymer includes about 0.5%to about 5%, preferably about 1% to about 3%, most preferably about 1%to 2% by weight MA-PP. The MA-PP can be compounded with the PPhomopolymer prior to adding the onium ion-intercalated clay, or theMA-PP and onium ion-intercalated clay can be combined first to form asolid, preferably powdered, mixture prior to combining the PPhomopolymer. Both methods of compounding give similar results. For thefollowing data a Leistrich 27 mm twin screw compounder with L/D 36:1 hasbeen used. Screws were used in co-rotating mode. A “standard” screwsconfiguration was employed, as shown in the following Table: EXTRUSIONCOMPOUNDING Compounder Screw and Zone Configuration Temperature Zone (°C.) Functions  4D 180 Conveying  8D 180 Conveying 12D 180 Conveying 16D180 Kneading/Dispersion 20D 180 Atmospheric Venting 24D 180 Conveying28D 180 Kneading/Dispersion 32D 185 Vacuum Devolitilization (26 in. Hg)36D 190 Conveying & Building Pressure Die 190 Strand Pelletizing

Example 15

[0115] Example 15 discloses the preparation of polyolefin/maleicanhydride-modified polyolefin emulsion with a cationic emulsifier whichcan also serve as the onium ion intercalant for the layered material.

[0116] Protonated octadecylamine (ODA) is used as an emulsifier toprepare the maleic anhydride-modified polypropylene (MA-PP) emulsion.Molten MA-PP is added to an ODA heated (e.g., 95-100° C., at ambientpressure) solution. The mixture is blended vigorously and reacted in apressurized container at a temperature of about 120-160° C. A stableemulsion is obtained. An aqueous montmorillonite clay dispersion isreacted with the ODA-MA-PP emulsion and a concentrate is obtained. Theproperties of the concentrate should be comparable to the propertiesobtained in the previous examples.

What is claimed is:
 1. A nanocomposite concentrate compositioncomprising about 10 weight percent to about 90 weight percent of alayered silicate material and about 90 weight percent to about 10 weightpercent of a matrix polymer comprising about 10-90% by weight of apolyolefin and about 90-10% by weight of a maleic anhydride-modifiedpolyolefin, based on the total weight of polyolefin and maleicanhydride-modified polyolefin in the matrix polymer, said layeredsilicate material intercalated with a polyolefin and a maleicanhydride-modified polyolefin, based on the total weight of polyolefinand maleic anhydride-modified polyolefin intercalated, wherein theintercalated layered silicate material is dispersed uniformly throughoutthe matrix polymer.
 2. A nanocomposite composition in accordance withclaim 1 , wherein the intercalated polyolefin is a polymer or oligomerof polypropylene.
 3. A nanocomposite composition in accordance withclaim 1 , wherein the layered silicate material is intercalated withonium ions that include at least one moiety covalently bonded to apositively charged nitrogen atom that has a length of at least sixcarbon atoms.
 4. A nanocomposite concentrate composition comprising amatrix polymer comprising a combination of about 95% to about 99.8% byweight of a polyolefin oligomer or polymer and about 0.5% to about 3% byweight of a maleic anhydride-modified polyolefin oligomer or polymer,said matrix polymer present in said nanocomposite concentrate in anamount of about 10% to about 90% by weight; and about 0.05% to about 60%by weight of an onium ion-intercalated phyllosilicate material formed bycontacting a phyllosilicate with onium ion ubtercalated layeredsilicate, wherein intercalation of the onium ions is achieved by contactof the phyllosilicate in an intercalating composition, having a molarratio of onium ions:phyllosilicate interlayer exchangeable cations of atleast about 0.25:1 to achieve ion-exchange of the onium ions betweenadjacent spaced platelets of the phyllosilicate to expand the spacingbetween a predominance of the adjacent phyllosilicate platelets at leastabout 3 Å, when measured after ion-exchange of the onium ions, and asecond intercalant disposed between adjacent spaced layers of thephyllosilicate material, said second intercalant comprising an olefinoligomer or polymer.
 5. A concentrate composition in accordance withclaim 4 , wherein the intercalated phyllosilicate is exfoliated into apredominance of individual platelets prior to adding matrix polymerthereto.
 6. A composition in accordance with claim 4 , wherein theolefiy oligomer or polymer second intercalant is a homopolymer orcopolymer selected from the group consisting of polypropylene,polyethylene, ethylene vinyl acetate, maleic anhydride-modifiedpolypropylene, maleic anhydride-modified polyethylene, a copolymer ofethylene and propylene, and mixtures thereof.
 7. A composition inaccordance with claim 6 , wherein the polypropylene second intercalantis intercalated into the phyllosilicate from an intercalatingcomposition containing said second intercalant in a concentration of atleast about 5% by weight, based on the dry weight of the phyllosilicatein the intercalating composition.
 8. A composition in accordance withclaim 6 , wherein the concentration of the second intercalant in saidintercalating composition is at least about 20% by weight, based on thedry weight of the phyllosilicate in the intercalating composition.
 9. Acomposition in accordance with claim 8 , wherein the concentration ofthe second intercalant in said intercalating composition is at leastabout 30% by weight, based on the dry weight of the phyllosilicate inthe intercalating composition.
 10. A composition in accordance withclaim 9 , wherein the concentration of the second intercalant in saidintercalating composition in the range of about 50% to about 80% byweight, based on the dry weight of the phyllosilicate in theintercalating compound.
 11. A composition in accordance with claim 9 ,wherein the concentration of the second intercalant in saidintercalating composition in the range of about 50% to about 200% byweight, based on the dry weight of the phyllosilicate in theintercalating composition.
 12. A composition in accordance with claim 4, wherein the molar ratio of intercalant onium ions:phyllosilicateinterlayer exchangeable cations is at least 0.5:1.
 13. A composition inaccordance with claim 4 , wherein the molar ratio of intercalant oniumions:phyllosilicate interlayer exchangeable cations is at least 1:1. 14.A composition in accordance with claim 4 , wherein the onium ions aremulti-onium ion compounds that include at least two primary, secondary,tertiary or quaternary ammonium, phosphonium, sulfonium, or oxoniumions.
 15. A composition in accordance with claim 4 , wherein the matrixpolymer polyolefin is selected from the group consisting ofpolyethylene, polypropylene, exthlene vinyl acetate, copolymers ofethylene and propylene, a composition in accordance with claim 4 ,wherein the olefin oligomer or polymer second intercalant is ahomopolymer or copolymer selected from the group consisting ofpolypropylene, polyethylene, ethylene vinyl acetate, maleicanhydride-modified polypropylene, maleic anhydride-modifiedpolyethylene, a copolymer of ethylene and propylene, and mixturesthereof.
 16. A nanocomposite concentrate composition comprising about10% by weight to about 90% by weight of a layered silicate materialreacted with a coupling agent, and co-intercalated with an onium ioncompound, and a polyolefin polymer or oligomer; and about 90 weightpercent to about 10 weight percent of a matrix polymer selected from thegroup consisting of a polyolefin oligomer or polymer, a maleicanhydride-modified oligomer or polymer and mixtures thereof; wherein theco-intercalated layered silicate material is dispersed uniformlythroughout the matrix polymer.
 17. A nanocomposite composition inaccordance with claim 16 , wherein the matrix polymer is intercalatedinto the layered silicate material.
 18. A nanocomposite composition inaccordance with claim 16 , wherein prior to intercalating the layeredmaterial with the polyolefin polymer, the layered material is firstintercalated with onium ions that include at least one moiety covalentlybonded to a positively charged nitrogen atom that has a length of atleast six carbon atoms.
 19. A method of increasing the strength of amatrix polymer comprising dispersing throughout said matrix polymer, inan amount of about 0.05% by weight to about 30% by weight, based on thetotal weight of the matrix polymer and the intercalate, an intercalateformed by intercalating an onium ion between layers of a phyllosilicate,and co-intercalating the phyllosilicate with a polyolefin, wherein thematrix polymer comprises a polyolefin and about 0.2% to 3% by weight ofa maleic anhydride-modified polyolefin, based on the total weight ofpolyolefin and maleic anhydride-modified polyolefin in the matrixpolymer.
 20. A method in accordance with claim 19 , wherein the matrixpolymer polyolefin is a polymer or oligomer selected from polyethylene,polypropylene, and a copolymer of ethylene and propylene.
 21. A methodin accordance with claim 20 , wherein the intercalant polyolefin ispolypropylene and wherein the polyolefin and the maleicanhydride-modified polyolefin of the matrix polymer both comprisepolypropylene.
 22. A method in accordance with claim 19 , wherein theonium ions include at least one moiety covalently bonded to a positivelycharged nitrogen atom that has a length of at least six carbon atoms.23. A method of manufacturing a composite material containing about 10%to about 99.95% by weight of a matrix polymer, and about 0.05% to about90% by weight of an onium ion-intercalated phyllosilicate material, saidmatrix polymer comprising 90-99.8% by weight polypropylene and 0.2-10%by weight maleic anhydride-modified polypropylene, comprising:intercalating the phyllosilicate material with onium ions, and thenmixing the matrix polymer, polyolefin and maleic anhydride-modifiedpolyolefin components, as melts, throughout said phyllosilicate toachieve intercalation of a portion of the matrix polymer, as meltedoligomers or melted polymers, between the phyllosilicate platelets. 24.A method in accordance with claim 23 , further including the steps of:reacting the phyllosilicate with a coupling agent; and contacting thephyllosilicate with an intercalant onium ion spacing agent, to achieveintercalation of said intercalant onium ion spacing agent between saidadjacent phyllosilicate platelets in an amount sufficient to space saidadjacent phyllosilicate platelets a distance of at least about 3 Å. 25.The method of claim 24 , wherein said phyllosilicate is contacted withsaid intercalant onium ion spacing agent, said phyllosilicate, and saidco-intercalants, and wherein the concentration of the onium ion spacingagent is in a molar ratio of onium ions:phyllosilicate interlayerexchangeable cations of at least 0.25:1.
 26. The method of claim 25 ,wherein the concentration of the onium ion spacing agent is in a molarratio of onium ions:phyllosilicate interlayer exchangeable cations of atleast 0.5:1.
 27. The method of claim 26 , wherein the concentration ofthe onium ion spacing agent is in a molar ratio of oniumions:phyllosilicate interlayer exchangeable cations of at least 1:1. 28.A method of manufacturing a composite material containing about 40% toabout 99.95% by weight of a matrix polymer comprising about 95% to about99.8% by weight polyolefin and about 0.2% to about 5% maleicanhydride-modified polyolefin, based on the total weight of polyolefinoligomers and polymers in the matrix polymer, and about 0.05% to about60% by weight of an intercalated phyllosilicate material, saidintercalated phyllosilicate having an intercalant onium ion spacingagent intercalated between adjacent phyllosilicate platelets comprising:contacting the phyllosilicate with an intercalating compositionincluding an intercalant onium ion spacing agent in a molar ratio ofonium ions:phyllosilicate interlayer cations of at least 0.25:1 toachieve intercalation of said intercalant onium ion spacing agentbetween said adjacent phyllosilicate platelets in an amount sufficientto space said adjacent phyllosilicate platelets at least an additional 3Å; combining the intercalated phyllosilicate with said polyolefin andmaleic anhydride-modified polyolefin matrix polymer, and heating thematrix polymer sufficiently to provide for flow of said matrix polymer;and dispersing said intercalated phyllosilicate throughout said heatedmatrix polymer.
 29. A method in accordance with claim 28 , wherein thecombined intercalated phyllosilicate and heated matrix polymer comprisesabout 10% to about 200% by weight of said matrix polymer, based on thedry weight of phyllosilicate.
 30. A method in accordance with claim 28 ,wherein the amount of onium ion spacing agent intercalated into thephyllosilicate material is in a molar ratio of at least 0.5:1, oniumions:exchangeable cations in the interlayer spaces of the phyllosilicatematerial.
 31. A method in accordance with claim 30 , wherein the amountof intercalant onium ion spacing agent intercalated into thephyllosilicate material is in a molar ratio of at least 1:1, oniumions:exchangeable cations in the interlayer spaces of the phyllosilicatematerial.
 32. A method in accordance with claim 31 , wherein the molarratio of intercalated onium ion spacing agent to interlayerphyllosilicate cations is from about 1:1 to about 1:5.
 33. A method inaccordance with claim 28 , wherein the weight ratio of the matrixpolymer to phyllosilicate material, dry basis, is from about 20 grams ofmatrix polymer co-intercalants per 100 grams of phyllosilicate materialto about 200 grams of matrix polymer per 100 grams of phyllosilicatematerial.
 34. A method in accordance with claim 28 , further includingcontacting the phyllosilicate with a coupling agent selected from thegroup consisting of an organosilane, an organotitanate, anorganoaluminate, an organozirconate, and mixtures thereof.
 35. A methodin accordance with claim 34 , wherein the coupling agent is anaminosilane.
 36. A method of manufacturing a composite concentratematerial containing about 40% to about 99.95% by weight of a polyolefinmatrix polymer, and about 0.05% to about 60% by weight of an onium ionintercalated and polyolefin co-intercalated phyllosilicate materialcomprising: intercalating the phyllosilicate material with an onium ionspacing agent by contacting the phyllosilicate with onium ions in amolar ratio of onium ions:phyllosilicate interlayer exchangeable cationsof at least 0.25:1; combining the onium ion-intercalated phyllosilicatematerial with a melt 10 of about 90% to about 99.8% by weight of apolyolefin and about 0.2% to about 10% by weight of maleicanhydride-modified polyolefin, based on the total weight of polyolefinsin the melt, to form said onium ion intercalated and polyolefinco-intercalated phyllosilicate material; and exfoliating a portion ofthe intercalated phyllosilicate.
 37. The method of claim 36 furtherincluding the step of adding more of the co-intercalants as matrixpolymer, after exfoliation of the intercalate, to form a nanocompositecomposition.
 38. The method of claim 36 , wherein the melt comprisesabout 95% to about 99.8% by weight of a polyolefin and about 0.2% toabout 5% by weight of a maleic anhydride-modified polyolefin.
 39. Themethod of claim 38 , wherein the melt comprises about 97% to about 99.8%by wight of a polyolefin and about 0.2% to about 3% by weight of amaleic anhydride-modified polyolefin.
 40. A nanocomposite concentratecomposition for combining with a maleic anhydride-modified polyolefin,such that after the addition of maleic anhydride-modified polyolefin,the polyolefin and the maleic anhydride-modified polyolefin are presentin the composition in a ratio of 0.2% to 10% by weight maleicanhydride-modified polyolefin to 90% to 99.8% by weight polyolefin, saidnanocomposite concentrate comprising: (a) an onium ion-exchanged layeredsilicate material intercalated with a polyolefin polymer or a polyolefinoligomer; and (b) a polyolefin matrix polymer or a polyolefin matrixoligomer, said intercalated layered silicate material and saidpolyolefin matrix polymer or matrix oligomer being present in thecomposition in a ratio of 20-80% by weight intercalated layered silicatematerial to 80-20% by weight polyolefin matrix polymer or oligomer. 41.The nanocomposite concentrate composition of claim 40 , furtherincluding about 0.2% to 10% maleic anhydride-modified polyolefin, basedon the total weight of polyolefin and maleic anhydride-modifiedpolyolefin.
 42. A nanocomposite concentrate composition for combiningwith a polyolefin oligomer or polyolefin polymer, such that a maleicanhydride-modified polyolefin and the polyolefin oligomer or polymer arcpresent in the composition in a ratio of 0.2% to 10% by weight maleicanhydride-modified polyolefin to 90% to 99.8% by weight polyolefinoligomer or polymer, said nanocomposite concentrate comprising: (a) anonium ion-exchanged layered silicate material intercalated with a maleicanhydride-modified polyolefin; and (b) a maleic anhydride-modifiedpolyolefin matrix polymer, or a maleic anhydride-modified matrixoligomer.
 43. The nanocomposite concentrate composition of claim 42 ,further including about 97% to 99.8% by weight polyolefin oligomer orpolyolefin polymer, based on the total weight of polyolefin and maleicanhydride-modified polyolefin.
 44. A nanocomposite concentratecomposition comprising: (a) an onium ion-exchanged layered silicatematerial intercalated with a polyolefin polymer or a polyolefinoligomer; and (b) a polyolefin matrix polymer or a polyolefin matrixoligomer, said intercalated layered silicate material and saidpolyolefin matrix polymer or matrix oligomer being present in thecomposition in a ratio of 20-80% by weight intercalated layered silicatematerial to 80-20% by weight polyolefin matrix polymer or oligomer. 45.A nanocomposite concentrate composition comprising: (a) an oniumion-exchanged layered silicate material intercalated with a maleicanhydride-modified polyolefin; and (b) a maleic anhydride-modifiedpolyolefin matrix polymer, or a maleic anhydride-modified matrixoligomer.
 46. A method of manufacturing a composite material containingabout 40% to about 99.95% by weight of a matrix polymer comprising about95% to about 99.8% by weight polyolefin and about 0.2% to about 10%maleic anhydride-modified polyolefin, based on the total weight ofpolyolefin oligomers and polymers in the matrix polymer, and about 0.05%to about 60% by weight of an intercalated phyllosilicate material, saidintercalated phyllosilicate having an intercalant emulsifying agentintercalated between adjacent phyllosilicate platelets comprising:mixing the phyllosilicate with water and an emulsifying agent to form anaqueous slurry of said phyllosilicate; mixing said polyolefin and maleicanhydride-modified polyolefin with an emulsifying agent to form anemulsion of said polyolefin and maleic anhydride-modified polyolefin toform a polymer emulsion, and dispersing said phyllosilicate throughoutsaid polymer emulsion.
 47. The method of claim 46 , wherein theemulsifying agent for both the phyllosilicate and for the polyolefins isa protonated amine compound.